On Mon, Jun 25, 2018 at 06:35:30AM -0700, Guenter Roeck wrote: > On 06/25/2018 05:26 AM, Christian Borntraeger wrote: > > > > > > On 06/25/2018 10:49 AM, Cornelia Huck wrote: > > > On Mon, 25 Jun 2018 10:36:33 +0200 > > > Vasily Gorbik <gor@xxxxxxxxxxxxx> wrote: > > > > > > > This change has been done on purpose. Uncompressed image is not going > > > > to be bootable any more. In future the decompressor phase would get > > > > more function (early memory detection as an example) and there is no > > > > chance to duplicate that code in uncompressed image as well (to keep it > > > > bootable on its own). The patch series commit messages contain more > > > > technical details. > > > > > > > > For qemu either bzImage or arch/s390/boot/compressed/vmlinux should be > > > > used, which are bootable images. > > > > > > > > But that's really confusing that uncompressed vmlinux is still kind > > > > of booting. May be we should discuss how to avoid this confusion > > > > (may be change uncompressed image enty point to a function doing > > > > disabled wait with badb007 or smth) and how to encourage people to use > > > > arch/s390/boot/compressed/vmlinux instead. > > > > > If an image is not expected to be bootable, a message such as "This image does > not boot. Please use <correct image>" would be nice. Unfortunately, which image > to boot under qemu is pretty much undocumented, and it is guesswork for each > architecture/platform. > > Guenter > > > I talked to Vasily and the vmlinux file in the linux source path is just an > > intermediate file. Future changes will happen that will make that ELF file > > unsuitable for direct boot anyway (e.g. think about potential ASLR or Kasan > > changes). > > > > If yes, it would make sense to explicitly fence it. But I'm > > > worried that it would break previously working setups (did we document > > > the purpose of the images anywhere? > > > To avoid confusion with trying to boot uncompressed vmlinux under qemu we could detect it and print "nice" message in the kernel. Please consider the following patch. Vasily Gorbik (1): s390/boot: block uncompressed vmlinux booting attempts arch/s390/boot/head.S | 4 ++-- arch/s390/include/asm/setup.h | 3 ++- arch/s390/kernel/early.c | 12 ++++++++++++ 3 files changed, 16 insertions(+), 3 deletions(-) -- ⣔⢻⣟⢢ 2.18.0.rc2.13.g4da9a5d ⣿⢿⡿⣿ pacman edition -- To unsubscribe from this list: send the line "unsubscribe linux-s390" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
